Twinning of two telephones allows a user to answer telephone calls at either device, typically by presenting the telephone call at a preferred device first or by presenting to the telephone call at both devices at the same time. The twinning of telephones is particularly useful for receiving telephone calls at alternate locations such as alternate office locations or when out of the office. Twinning of a land line and a cellular telephone, for example, allows a user to answer calls at either device, depending on location or mobility requirements.
After answering a telephone call at one of the twinned devices, the user must continue the call on the device used for answering until the call is completed (i.e. until the user hangs up or transfers the telephone call). It will be appreciated, that in some cases it is desirable to transfer the call to the other of the twinned devices. For example, a user that answers a telephone call on a land line may wish to move the call to a cellular telephone for added mobility. On the other hand a user who answers a telephone call on a cellular telephone may wish to move the call to a land line to take advantage of device features and capabilities such as speakerphone capability or a conference unit.
In many prior art systems, such a device change is not possible and the user must cope with continuing the telephone call at the original device rather than changing devices.
To address this issue, a user is forced to arrange an alternate telephone call with the other party by advising the other party that they will call back on another line to continue the conversation. Of course, the user can also ask the other party to call back to allow the user to answer on the alternate line. The original telephone call is then terminated and another telephone call is established by initiating or answering the call on the other telephone device. In some cases, the conversation is not continued due to the arrival of another call in the meantime or due to an interruption or other event resulting in the call not being initiated or not getting through.
Where both telephone devices are locally supported by a PBX with enabling features, a user can place the original call on hold and then initiate a remote retrieve of the held call from the other device. This requires both feature support within the PBX and an understanding of the feature by the user including feature access codes and dialing sequence to retrieve the call.
In another approach to addressing this issue, a conference is established involving both of the user devices and the other party. Such a conference again requires feature support within the PBX. As with remote retrieve, this approach requires user understanding of the conference feature.
A different technique for switching telephone communication from one twinned device to another is desirable.